The present invention relates to a digital audio signal player having a simulated analogue record, which is equipped with a turnable control element to be turned by a DJ to simulate an analogue record player being moved on the turntable by the DJ so that music is played with tone and speed being changed in accordance with the movement of the control element, more particularly the present invention provides a digital audio signal player having a simulated analogue record of the above mentioned nature that is not subject to interference of the ground lead of power cords thereof or magnetic interference of people and electronic equipments in the vicinity thereof
In order to help increase hot and exciting atmosphere in a concert or a party such as is held in a PUB or a dancing hall, the DJ would make the music played with changing tone and speed by means of moving the analogue record on the turntable in various ways. When the DJ stoops moving the record with his hands, the record will be played on the record player in a normal way immediately.
However, a single analogue record has very limited capacity for storing music, therefore the DJ has to prepare a lot of records in each party that are likely to cause him inconvenience due to the large size and heavy weight.
In order to overcome the above disadvantages, the inventor of the present invention had disclosed a digital audio signal player having a simulated analogue record, which includes a driving IC 11, a CD driving motor 111, a turntable 112, an ejection motor 113, a laser pick-up 114, a laser pick-up moving motor 115, a microprocessor 12, a control panel 121, a high frequency amplifier 13, a CD digital processor 14, a digital audio signal processor 15, a dynamic RAM 151, a digital/analog converter 17, a turnable control element 16, an interfering signal detecting circuit 163 and a low pass filter 18.
The turntable 112 is provided for holding an analogue CD, and connected to the CD driving motor 111. The driving IC 11 is electrically connected to the CD driving motor 111, and the ejection motor 113 for activating the same to turn the turntable 112, and to eject the turntable 112 for removal of the CD respectively.
When the microprocessor 12 is activated, the same will make the high frequency amplifier 13 send out laser light, and activate the laser pick-up 114 by means of both the CD digital processor 14 and the driving IC 11. The driving IC 11 will also activate the laser pick-up moving motor 115 to move the laser pick-up 114. The laser pick-up 114 sends a signal to the CD digital processor 14 via the high frequency amplifier 13 such that the CD digital processor 14 can inform the microprocessor 12 whether the laser light has focused; if the laser light fails to focus, the microprocessor 12 will stop; if the laser light focuses successfully, the microprocessor 12 will activate the CD digital processor 14 so that the processor 14 makes the driving IC 11 activate the CD driving motor 111; the analogue CD positioned on the turntable 112 is rotated at two times the normal speed when the CD driving motor 111 is activated. And, the laser pick-up 114 reads the data of the analogue CD, and sends the data to both the microprocessor 12 and the digital audio signal processor 15 via the high frequency amplifier 13 and the CD digital processor 14; the microprocessor 12 will also make the control panel 121, which is electrically connected to it, show information about the CD; the digital audio signal processor 15 will store the data of the CD in the dynamic RAM 151.
The turnable control element 16 is made of conductive materials and formed with a round shape, and is electrically connected to the digital audio signal processor 15. The control element 16 normally sends out an original signal 161, and will send out an interfering signal 162, which is stronger than the signal 161, when the same is touched by a person's hand. A sensor (not shown) of the control element 16 will sense the rotating speed and direction of the control element 16. The interfering signal 162 will be processed by the interfering signal detecting circuit 163, and then sent to the microprocessor 12. The digital/analog converter 17 is electrically connected to both the digital audio signal processor 15 and the low pass filter 18. The microprocessor 12 can make comparison between the signal 161 and the interfering signal 162, and determine that a user has touched the control element 16 if the difference between the signal 161 and the interfering signal 162 exceeds a predetermined amount.
Thus, when a user such as a DJ rotates the turnable control element 16 with the hands, the digital audio signal processor 15 will process and sent out the data stored in the dynamic RAM 151 in a manner according to the movement of the control element 16 as sensed by the sensor, i.e. the user can control the speed and direction of the data send out from the digital audio signal processor 15. Then, the data is converted into analogue ones by means of the digital/analog converter 17. And, the analogue data are processed by the low pass filter 18, and played as music. When the user stops touching or moving the control element 16, the interfering signal 162 will disappear immediately, and accordingly the microprocessor 12 and the digital audio signal processor 15 will begin to play the music in the normal way.
Although the above player with simulated analogue record can play music with changing direction and speed to help increase hot and exciting atmosphere when a DJ rotate the turnable control element 16 to simulate a record being rotated by the hand, it is found to have a disadvantage that the interfering signal detecting circuit 163 will sense other magnetic interference that is produced by the crowd and various electronic equipments in a dancing hall, thus wrongly deciding that the control element 16 is being touched by hands.
To overcome the disadvantages of the above digital audio signal player, referring to FIG. 5, the inventor of the present invention had used another device instead of the above interfering signal detecting circuit 163 to work together with the microprocessor 12 for accurately detecting contact of hands with the control element 16. The device includes a diode 191, a buffer 192, and a high frequency alternator 19, which are connected to the microprocessor 12. And, the high frequency alternator 19 constantly sends out a high frequency signal, and is electrically connected to P pole of the diode 19, which is connected in series with the buffer 192, at the output terminal thereof. The turnable control element 16 is also connected to the P pole of the diode 191 from an output terminal thereof. Music is played in a normal way when the microprocessor 12 receives the high frequency signal in a non-reduced form; the turnable control element 16 will send an interfering signal to the diode 191 so as to reduce the high frequency signal passing through the diode 191 when touched by a hand of a person, thus making the microprocessor 12 receive a high frequency signal in a reduced form from the high frequency alternator 19 so that music is played with speed and direction changing according to the movement of the turnable control element 16 as sensed by means of a light sensitive device 164 connected to the control element 16. Thus, the microprocessor 12 is not subject to magnetic interference of people and electronic equipments to wrongly make music played with changed speed and direction when the DJ doesn't intend to. However, the above audio signal player still has a drawback that the high frequency alternator 19 thereof is subject to interference of the ground lead of the power cords thereof, thus wrongly deciding that the control element 16 is being touched by hands when it actually isn't.